Azeotrope-like compositions of difluoromethane and trifluoroiodomethane

ABSTRACT

Provided are azeotrope-like compositions comprising difluoromethane and trifluoroiodomethane and uses thereof, including use in refrigerant compositions, refrigeration systems, blowing agent compositions, and aerosol propellants.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a Continuation in Part of each of U.S.application Ser. No. 10/826,811, now U.S. Pat. No. 7,413,674, Ser. No.10/826,072, now U.S. Pat. No. 7,074,751, Ser. No. 10/826,727, nowabandoned, Ser. No. 10/826,592, now U.S. Pat. No. 6,969,701, and Ser.No. 10/826,597, now U.S. Pat. No. 7,098,176, all of which were filed onApr. 16, 2004. The present application is also related to and claims thepriority benefit of U.S. Provisional Patent Application Ser. No.60/563,085 filed Apr. 16, 2004. The disclosures of all six applicationsare incorporated herein by reference.

Also incorporated herein by reference are the following U.S.applications identified by Ser. Nos. 11/109,575; 11/109,195; 11/109,187;11/109,188, 11/109,189 and 11/109,190, each of which is filedconcurrently herewith.

FIELD OF INVENTION

The present invention provides azeotrope-like compositions ofdifluoromethane and trifluoroiodomethane, and uses thereof.

BACKGROUND

Fluorocarbon based fluids have found widespread use in industry in anumber of applications, including as refrigerants, aerosol propellants,blowing agents, heat transfer media, and gaseous dielectrics. Because ofthe suspected environmental problems associated with the use of some ofthese fluids, including the relatively high ozone depletion potentialsassociated therewith, it is desirable to use fluids having low or evenzero ozone depletion potential, such as hydrofluorocarbons (“HFCs”).Thus, the use of fluids that do not contain chlorofluorocarbons (“CFCs”)or hydrochlorofluorocarbons (“HCFCs”) is desirable. Furthermore, someHFC fluids may have relatively high global warming potentials associatedtherewith, and it is desirable to use hydrofluorocarbon or otherfluorinated fluids having as low global warming potentials as possiblewhile maintaining the desired performance in use properties.Additionally, the use of single component fluids or azeotrope-likemixtures, which do not substantially fractionate on boiling andevaporation, is desirable. However, the identification of new,environmentally-safe, non-fractionating mixtures is complicated due tothe fact that azeotrope formation is not readily predictable.

The industry is continually seeking new fluorocarbon based mixtures thatoffer alternatives, and are considered environmentally safer substitutesfor CFCs and HCFCs. Of particular interest are mixtures containing bothhydrofluorocarbons and other fluorinated compounds, both of low ozonedepletion potentials. Such mixtures and their uses are the subject ofthis invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present inventors have developed several compositions that help tosatisfy the continuing need for alternatives to CFCs and HCFCs.According to certain embodiments, the present invention providesazeotrope-like compositions comprising difluoromethane (“HFC-32”) andtrifluoroiodomethane (“CF₃I”).

The preferred compositions of the invention exhibit a number ofcharacteristics that allow them to be used to great advantage in anumber of applications, including as replacements for CFCs, such asdichlorodifluoromethane (CFC-12), HCFCs, such as chlorodifluoromethane(HCFC-22), HFCs, such as tetrafluoroethane (HFC-134a), and combinationsof HFCs and CFCs, such as the combination of CFC-12and 1,1-difluorethane(HFC-152a) (the combination CFC-12:HFC-152a in a 73.8:26.2 mass ratiobeing known as R-500) in refrigerant, aerosol, and other applications.

For example, the present compositions tend to be both non-flammable andto exhibit relatively low global warming potentials (“GWPs”), preferablylower than the GWP of HFC-32 alone, preferably less than about 1000,more preferably less than about 500, and even more preferably less thanabout 150.

Additionally, applicants have recognized surprisingly thatazeotrope-like compositions of HFC-32 and CF₃I can be formed.Accordingly, in other embodiments, the present invention providesmethods of producing an azeotrope-like composition comprising combiningHFC-32 and CF₃I in amounts effective to produce an azeotrope-likecomposition.

In addition, applicants have recognized that the azeotrope-likecompositions of the present invention exhibits properties that make thatmake them advantageous for use as, or in, numerous applications,including as heat transfer compositions (including as refrigerants inautomotive air conditioning and heat pump systems, and in stationary airconditioning, heat pump and refrigeration systems), blowing agents,propellants and sterilizing agents. Accordingly, in yet otherembodiments, the present invention provides compositions and methodsassociated with these and other uses.

Azeotrope-Like Compositions

As used herein, the term “azeotrope-like” is intended in its broad senseto include both compositions that are strictly azeotropic andcompositions that behave like azeotropic mixtures. From fundamentalprinciples, the thermodynamic state of a fluid is defined by pressure,temperature, liquid composition, and vapor composition. An azeotropicmixture is a system of two or more components in which the liquidcomposition and vapor composition are equal at the stated pressure andtemperature. In practice, this means that the components of anazeotropic mixture are constant-boiling and cannot be separated during aphase change.

The azeotrope-like compositions of the invention may include additionalcomponents that do not form new azeotrope-like systems, or additionalcomponents that are not in the first distillation cut. The firstdistillation cut is the first cut taken after the distillation columndisplays steady state operation under total reflux conditions. One wayto determine whether the addition of a component forms a newazeotrope-like system so as to be outside of this invention is todistill a sample of the composition with the component under conditionsthat would be expected to separate a non-azeotropic mixture into itsseparate components. If the mixture containing the additional componentis non-azeotrope-like, the additional component will fractionate fromthe azeotrope-like components. If the mixture is azeotrope-like, somefinite amount of a first distillation cut will be obtained that containsall of the mixture components that is constant boiling or behaves as asingle substance.

It follows from this that another characteristic of azeotrope-likecompositions is that there is a range of compositions containing thesame components in varying proportions that are azeotrope-like orconstant boiling. All such compositions are intended to be covered bythe terms “azeotrope-like” and “constant boiling”. As an example, it iswell known that at differing pressures, the composition of a givenazeotrope will vary at least slightly, as does the boiling point of thecomposition. Thus, an azeotrope of A and B represents a unique type ofrelationship, but with a variable composition depending on temperatureand/or pressure. It follows that, for azeotrope-like compositions, thereis a range of compositions containing the same components in varyingproportions that are azeotrope-like. All such compositions are intendedto be covered by the term azeotrope-like as used herein.

It is well-recognized in the art that it is not possible to predict theformation of azeotropes. (See, for example, U.S. Pat. No. 5,648,017(column 3, lines 64-65) and U.S. Pat. No. 5,182,040 (column 3, lines62-63), both of which are incorporated herein by reference). Applicantshave discovered unexpectedly that HFC-32 and CF₃I from azeotrope-likecompositions.

According to certain preferred embodiments, the azeotrope-likecompositions of the present invention comprise, and preferably consistessentially of, effective azeotrope-like amounts of HFC-32 and CF₃I. Theterm “effective azeotrope-like amounts” as used herein refers to theamount of each component which upon combination with the othercomponent, results in the formation of an azeotrope-like composition ofthe present invention. Preferably, the present azeotrope-likecompositions comprise, and preferably consist essentially of, from about67 to less than 100 weight percent HFC-32 and from greater than zero toabout 33 weight percent of CF₃I. More preferably, the azeotrope-likecompositions comprise, and preferably consist essentially of, from about73 to about 99 weight percent HFC-32 and from about 1 to about 27 weightpercent of CF₃I, and even more preferably from about 85 to about 99weight percent HFC-32 and from about 1 to about 15 weight percent ofCF₃I. Unless otherwise indicated, the weight percents disclosed hereinare based on the total weight of HFC-32 and CF₃I in a composition.

The azeotrope-like compositions described herein preferably have aboiling point of from about −55° C. to about −51 ° C. at a pressure ofabout 14.51 psia. In certain more preferred embodiments, the presentazeotrope-like compositions have a boiling point of from about −55° C.to about −52° C. at a pressure of about 14.51 psia, and in even morepreferred embodiments, from about −54° C. to about −53° C. at a pressureof about 14.51 psia.

The azeotrope-like compositions of the present invention can be producedby combining effective azeotrope-like amounts of HFC-32 and CF₃I. Any ofa wide variety of methods known in the art for combining two or morecomponents to form a composition can be adapted for use in the presentmethods to produce an azeotrope-like composition. For example, HFC-32and CF₃I can be mixed, blended, or otherwise combined by hand and/or bymachine, as part of a batch or continuous reaction and/or process, orvia combinations of two or more such steps. In light of the disclosureherein, those of skill in the art will be readily able to prepareazeotrope-like compositions according to the present invention withoutundue experimentation.

Composition Additives

The azeotrope-like compositions of the present invention may furtherinclude any of a variety of optional additives including lubricants,stabilizers, metal passivators, corrosion inhibitors, flammabilitysuppressants, and the like.

According to certain embodiments, the azeotrope-like compositions of thepresent invention further comprise a stabilizer. Any of a variety ofcompounds suitable for stabilizing an azeotrope-like composition of thepresent invention may be used. Examples of certain preferred stabilizersinclude stabilizer compositions comprising stabilizing diene-basedcompounds, and/or phenol compounds, and/or epoxides selected from thegroup consisting of aromatic epoxides, alkyl epoxides, alkenyl epoxides,and combinations of two or more thereof.

As the term is used herein, “diene-based compound” refers to C3-C5dienes and to compounds formed by reaction of any two or more C3-C5dienes. In the case of diene-based compounds which are formed by acombination of C3-C5 dienes, the molecules which are combined can be thesame or different. Certain of the preferred compositions comprise atleast one diene-based compound in an amount effective under conditionsof use to stabilize the iodocarbon against degradation. The type andnature of the diene-based compound(s) to be used may depend, to at leastsome degree, upon the particular iodocarbon compound(s) being used inthe composition, the expected conditions of use of the compositions, andrelated factors.

It is generally contemplated that the amount of the diene-basedstabilizer used in the compositions of the present invention can varywidely, depending upon factors such as the type and/or amounts ofiodocarbon compounds in the composition, the expected conditions of useof the composition, among other factors. In general, it is preferred touse diene-based stabilizer in an effective amount relative to theiodocarbon being used. As used herein, the term “effective amount”refers to an amount of diene-based compound(s) which, when added to acomposition comprising the relevant iodocarbon compound, such astrifluoroiodomethane, results in a stabilized composition wherein theiodocarbon degrades more slowly and/or to lesser degree relative to thesame composition, under the same, or similar, conditions, but in theabsence of the diene-based compounds. In the particular example oftrifluoroiodomethane, one of the important potential breakdown productsunder certain severe conditions is trifluoromethane, which is formed bythe substitution of hydrogen for iodine in the CF₃I molecule. Similarly,hydrogen can be substituted for iodine in other iodocarbons, therebyforming compounds that can have GWP values greater than 150. Thesebreakdown products have the effect of raising the GWP of the refrigerantblends that use iodocarbons. The goal of having a low global warmingpotential is therefore defeated. An effective amount of stabilizer willreduce the amount of decomposition of the iodocarbon such that the GWPof the refrigerant composition is below 150. Even without theconsideration of GWP values, breakdown of a component of a refrigerantcomposition is undesirable. Thus it is preferred that the level of thebreakdown product described above be less than 1.0 wt. % of the totalrefrigerant composition. In certain preferred embodiments, the amount ofthe diene-based compound(s) is sufficient to result in a stabilizedcomposition wherein at least one of the iodocarbon compound(s) thereindegrades more slowly and/or to a lesser degree relative to the samecomposition but in the absence of the diene-base compound, when testedaccording to SAE J1662 (issued June 1993) and/or ASHRAE 97-1983Rstandard tests. For example, in certain preferred embodiments, theamount of breakdown product, that is product formed by the substitutionof hydrogen for iodine in the iodocarbon, is less than about 0.9 wt. %after the composition is maintained at about 300° F. for about twoweeks.

In certain preferred embodiments, the diene-based compounds are presentin the composition in amounts of from about 0.001% to about 10% byweight, more preferably from about 0.01 wt. % to about 5 wt. %, and evenmore preferably from about 0.3 wt. % to about 4 wt. %, based on thetotal weight of refrigerant composition that is comprised of theiodocarbon.

In preferred embodiments the diene-based compounds are selected from thegroup consisting of allyl ethers, propadiene, butadiene, isoprene,terpenes such as myrcene, terpene derivatives and combinations of anytwo or more of these. As used herein, each of the compounds identifiedin the immediately preceding list is intended to include bothsubstituted and unsubstituted forms of the identified compounds. Incertain preferred embodiments, the diene-based compounds comprise inmajor proportion, and even more preferably consist essentially of,propadiene.

In certain other preferred embodiments, the diene-based compoundscomprise in major proportion, and even more preferably consistessentially of, terpenes, terpene derivatives or combinations of these.As used herein, the term “terpene” means a compound, which is comprisedof at least ten carbon atoms and contains at least one, and preferablyat least two isoprene moieties. In many preferred embodiments, theterpene compound of the present invention is formed from the reaction ofat least two isoprene C5 units (CH2═C(CH3)—CH═CH2) (each unit beingsubstituted or unsubstituted), and thus many of the terpene compounds ofthe present invention preferably have as at least 10 carbon atoms andinclude at least one isoprene moiety. As used herein, the term “isoprenemoiety” refers to any portion of a molecule, which includes a radical,which can be formed from substituted or unsubstituted isoprene. Incertain preferred embodiments, unsubstituted terpenes are preferred.

In many preferred embodiments, the terpene compound of the presentinvention comprises at least one head-to-tail condensation product ofmodified or unmodified isoprene molecules. It is contemplated that anyone or more terpene compounds are adaptable for use in accordance withthe present invention and that those skilled in the art will be able, inview of the teachings contained herein, to select the number and type ofterpene compound(s) for any particular application without undueexperimentation. The preferred terpenes of the present invention arehydrocarbons having molecular formula (C₅H₈)_(n) in a cyclic or acyclic,saturated or unsaturated, substituted or unsubstituted structure, with npreferably being from 2 to about 6, and even more preferably 2 to 4.Terpenes according to the present invention having the formula C₁₀H₁₆(including substituted forms) are sometimes referred to herein asmonoterpenes, while terpenes having the formula C₁₅H₂₄ (includingsubstituted forms) are sometimes referred to herein as sesquiterpenes.Terpenes according to the present invention having the formula C₂₀H₃₂(including substituted forms) are sometimes referred to herein asditerpenes, while terpenes having the formula C₃₀H₄₈ (includingsubstituted forms) are sometimes referred to as triterpenes, and so on.Terpenes containing 30 or more carbons are usually formed by the fusionof two terpene precursors in a regular pattern. While it is contemplatedthat all such terpenes are adaptable for use in accordance with thepresent invention, the use of monoterpenes is generally preferred.

In certain preferred embodiments, the terpene compound(s) of presentcompositions comprise, preferably in major proportion, and even morepreferably consist essentially of, one or more acyclic terpenecompounds. Among the acyclic terpenes, it is contemplated that suchcompounds may be within the class of compounds identified ashead-to-tail linked isoprenoids or within the class of compounds thatare not joined in that manner. Acyclic terpenes which are preferred foruse in accordance with certain aspects of the present invention includemyrcene (2-methyl-6-methyleneocta-1,7-diene), allo-cimene, beta-ocimene.

In certain embodiments, the terpene compounds of the present inventionmay comprise cyclic terpene compounds. Among the cyclic terpenes, mono-,bi-, tri-, or tetracyclic compounds having varying degrees ofunsaturation are contemplated for use in accordance with the presentinvention.

Examples of terpene compounds adaptable for use in connection with thevarious aspects of the present invention include terebene, myrcene,limonene, retinal, pinene, menthol, geraniol, farnesol, phytol, VitaminA₁, terpinene, delta-3 carene, terpinolene, phellandrene, fenchene, andthe like, as well as blends thereof, including all their isomers.

Examples of terpene derivatives in accordance with the present inventioninclude oxygen-containing derivatives of terpenes such as alcohols,aldehydes or ketones containing hydroxyl groups or carbonyl groups, aswell as hydrogenated derivates. Oxygen-containing derivatives ofterpenes are sometimes referred to herein as terpenoids. In certainembodiments, the diene-based compounds of the present invention comprisethe terpenoid Carnosic acid. Carnosic acid is a phenolic diterpene thatcorresponds to the empirical formula C2028O4. It occurs naturally inplants of the Libiatae family. For instance, carnosic acid is aconstituent of the species Salvia officinalis (sage) and Rosmarinusofficinalis (rosemary) where it is mainly found in the leaves. Carnosicacid is also found in thyme and marjoram. It was discovered by Linde inSalvia officinalis [Helv. Chim Acta 47, 1234 (1962)] and by Wenkert etal. in Rosmarinus officinalis [J. Org. Chem. 30, 2931 (1965)]. It wasthen positively identified in various other species of sage, such as forexample Salvia canariensis [Savona and Bruno, J. Nat. Prod. 46, 594(1983)] or Salvia willeana[de la Torre et al., Phytochemistry 29, 668(1990)]. It is also present in Salvia triloba and Salvia sclarea.

Any suitable relative amount of the at least one diene-based compoundand supplemental optional stabilizer compound(s) may be used. Forexample, in certain preferred embodiments the weight ratio of thediene-based compound(s) to other stabilizer compound(s) is in the rangeof from about 1:99 to about 100:0. In more preferred embodiments, theweight ratio of diene-based compound(s) to the optional stabilizers isfrom about 10:1 to about 1:1, more preferably from about 2:1 to about1:1, and even more preferably about 1:1.

Preferred terpene stabilizers are disclosed in U.S. Provisional PatentApplication No. 60/638,003, filed on Dec. 12, 2004, which isincorporated herein by reference.

Any of a variety of phenol compounds and/or epoxides is suitable alsofor use as stabilizers in the present compositions. While applicants donot wish to be bound by or to any theory of operation, it is believedthat the present phenols act as radical scavengers in the CF₃Icompositions and thereby tend to increase the stability of suchcompositions. As used herein the term “phenol compound” refers generallyto any substituted or unsubstituted phenol. Examples of suitable phenolcompounds include phenols comprising one or more substituted orunsubstituted cyclic, straight-chain, or branched aliphatic substituentgroup, such as, alkylated monophenols including:2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-4-ethylphenol;2,4-dimethyl-6-tert-butylphenol; tocopherol; and the like, hydroquinoneand alkylated hydroquinones including: t-butyl hydroquinone; otherderivatives of hydroquinone; and the like, hydroxylated thiodiphenylethers including: 4,4′-thiobis (2-methyl-6-tert-butylphenol);4,4′-thiobis (3-methyl-6-tert-butylphenol); 2,2′-thiobis(4-methyl-6-tert-butylphenol); and the like, alkylidene-bisphenolsincluding: 4,4′-methylenebis(2,6-di-tert-butylphenol);4,4′-bis(2,6-di-tert-butylphenol; derivatives of 2,2- or4,4-biphenyldiols; 2,2′-methylenebis(4-ethyl-6-tertbutylphenol);2,2′-methylenebis(4-methyl-6-tert-butylphenol);4,4,-butylidenebis(3-methyl-6-tert-butylphenol);4,4,-isopropylidenebis(2,6-di-tert-butylphenol);2,2′-methylenebis(4-methyl-6-nonylphenol);2,2′-isobutylidenebis(4,6-dimethylphenol);2,2′-methylenebis(4-methyl-6-cyclohexylphenol), 2,2- or4,4-biphenyldiols including2,2′-methylenebis(4-ethyl-6-tertbutylphenol), butylated hydroxy toluene(BHT), bisphenols comprising heteroatoms including:2,6-di-tert-.alpha.-dimethylamino-p-cresol;4,4-thiobis(6-tert-butyl-m-cresol); and the like; acylaminophenols;2,6-di-tert-butyl-4(N,N′-dimethylaminomethylphenol); sulfides including:bis(3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide;bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide; and the like; as well as,phenolic UV absorb and light stabilizers. Certain preferred phenolsinclude alkylated monophenols such as tocopherol, BHT, hydroquinones,and the like. Certain particularly preferred phenols include tocopherol,and the like. Most phenols are commercially available. A single phenolcompound and/or mixtures of two or more phenols may be used in thepresent compositions. Any of a variety of epoxides is suitable for usein the compositions of the present invention. While applicants do notwish to be bound by or to any theory of operation, it is believed thatthe epoxides of the present invention act as acid scavengers in theiodcarbon compound, such as CF₃I, in the present compositions andthereby tend to increase the stability of such compositions. A singlearomatic epoxide and/or mixtures of two or more aromatic epoxides may beused in the present compositions.

Examples of suitable aromatic epoxides include those defined by theformula I below:

wherein: R is hydrogen, hydroxyl, alkyl, fluoroalkyl, aryl, fluoroaryl,or

Ar is a substituted or unsubstituted phenylene or napthylene moiety.Certain preferred aromatic epoxides of Formula I include those whereinAr is phenylene or phenylene substituted with one or more substituentsincluding alkyls, alkenyls, alkynyls, aryls, alkylaryls, halogens,halogenated alkyls, halogenated alkenyls, halogenated alkynyls,halogenated aryls, halogenated arylalkyls, hydroxyls, heteroatommoieties, and the like. Examples of suitable compounds of Formula Iwherein Ar is an unsubstituted or substituted phenylene includebutylphenylglycidyl ether; pentylphenylglycidyl ether;hexylphenylglycidyl ether; heptylphenylglycidyl ether;octylphenylglycidyl ether; nonylphenylglycidyl ether;decylphenylglycidyl ether; glycidyl methyl phenyl ether; 1,4-diglycidylphenyl diether; 4-methoxyphenyl glycidyl ether; derivatives thereof; andthe like.

Certain other preferred aromatic epoxides of Formula I include thosewherein Ar is napthylene or napthylene substituted with one or moresubstituents including alkyls, alkenyls, alkynyls, aryls, alkylaryls,halogens, halogenated alkyls, halogenated alkenyls, halogenatedalkynyls, halogenated aryls, halogenated arylalkyls, hydroxyls,heteroatom moieties, and the like. Examples of suitable compounds ofFormula I wherein Ar is an unsubstituted or substituted napthyleneinclude naphthyl glycidyl ether; 1,4-diglycidyl naphthyl diether;derivatives thereof; and the like.

Examples of other suitable aromatic epoxides include bisoxiranes, suchas,2,2′[[[5-heptadecafluorooctyl]1,3phenylene]bis[[2,2,2trifluoromethyl]ethylidene]oxymethylene]bisoxirane;and the like.

In certain preferred embodiments, the aromatic epoxides for use in thepresent invention comprise an epoxide of Formula I wherein Ar isphenylene, substituted phenylene, napthylene, or substituted napthylene.More preferably, the aromatic epoxides comprise an epoxide of Formula Iwherein Ar is phenylene or substituted phenylene. Examples of certainmore preferred aromatic epoxides include butylphenyl glycidyl ether, andthe like.

Any of a variety of alkyl and/or alkenyl epoxides are suitable for usein the present compositions. Examples of suitable alkyl and alkenylepoxides include those of Formula II:

wherein R_(alk) is a substituted or unsubstituted alkyl or alkenylgroup. Certain preferred epoxides of Formula II comprise alkyl epoxidecompounds wherein R_(alk) is an alkyl group having from about 1 to about10 carbon atoms, more preferably from about 1 to about 6 carbon atoms,and wherein the alkyl may be unsubstituted or further substituted withone or more substituents including alkyls, alkenyls, alkynyls, aryls,alkylaryls, halogens, halogenated alkyls, halogenated alkenyls,halogenated alkynyls, halogenated aryls, halogenated arylalkyls,hydroxyls, heteroatom moieties, and the like. Examples of such preferredalkyl epoxides of Formula II include n-butyl glycidyl ether, isobutylglycidyl ether, hexanediol diglycidyl ether, and the like, as well as,fluorinated and perfluorinated alkyl epoxides, and the like. Certainmore preferred alkyl epoxides comprise hexanediol diglycidyl ether, andthe like.

Certain other preferred epoxides of Formula II comprise alkenyl epoxidecompounds wherein R_(alk) is an alkenyl group having from about 1 toabout 10 carbon atoms, more preferably from about 1 to about 6 carbonatoms, and wherein the alkenyl may be unsubstituted or furthersubstituted with one or more substituents including alkyls, alkenyls,alkynyls, aryls, alkylaryls, halogens, halogenated alkyls, halogenatedalkenyls, halogenated alkynyls, halogenated aryls, halogenatedarylalkyls, hydroxyls, heteroatom moieties, and the like. Examples ofsuch preferred alkenyl epoxides of Formula II include allyl glycidylether, fluorinated and perfluorinated alkenyl epoxides, and the like.More preferred alkenyl epoxides include allyl glycidyl ether, and thelike. A single alkyl epoxide or alkenyl epoxide and/or combinations oftwo or more thereof may be used in the present compositions.

In certain other preferred embodiments, the alkyl epoxide for use as anacid scavenger in the present composition comprises polypropylene glycoldiglycidyl ether. Examples of polypropylene glycol diglycidyl ethersuitable for use in the present invention includes the ether availablecommercially from SACHEM, Europe.

In addition, in certain embodiments, the epoxide for use in the presentinvention comprises combinations of two or more aromatic, alkyl, and/oralkenyl substituents. Such epoxides are referred to generally as“multisubstituted epoxides.”

According to certain preferred embodiments, the stabilizer for use inthe present invention comprises one or more diene-based compounds,preferably a terpene and/or a terpene-based compound. In certainembodiments the stabilizer comprises such diene-based compound(s) in acombination with at least one phosphite compound, and/or at least onephenol compound and/or at least one aromatic, alkyl, or alkenyl epoxide.Examples of suitable combinations include stabilizers comprising:tocopherol and allyl glycidyl ether, BHT and glycidyl butyl ether, andthe like. Certain particularly preferred combinations includestabilizers comprising: tocopherol and allyl glycidyl ether, and thelike. In certain embodiments the preferred stablizers comprise at leastone diene-based compound in combination with at least one phosphitecompound.

Any suitable relative amount of the at least one phenol compound and theat least one aromatic, alkyl, or alkenyl epoxide may be used in thepreferred stabilizers. For example, the weight ratio of phenolcompound(s) to aromatic or fluorinated alkyl epoxide(s) can be variedfrom about 1:99 to about 99:1. In certain preferred embodiments, theweight ratios of phenol compound(s) to aromatic, alkyl, alkenyl,multisubstituted, or fluorinated alkyl epoxide(s) is from about 30 toabout 1, more preferably from about 7 to about 1, more preferably fromabout 2 to about 1, and even more preferably about 1:1.

Any suitable effective amount of stabilizer may be used in thetrifluoroiodomethane compositions of the present invention. As usedherein, the term “effective stabilizing amount” refers to an amount ofstabilizer of the present invention which, when added to a compositioncomprising trifluoroiodomethane, results in a stabilized compositionwherein the trifluoroiodomethane therein degrades more slowly and/or toa lesser degree relative to the original composition, under the same, orsimilar, conditions. In certain preferred embodiments, an “effectivestabilizing amount” of stabilizer comprises an amount which, when addedto a composition comprising trifluoroiodomethane, results in astabilized composition wherein the trifluoroiodomethane therein degradesmore slowly and/or to a lesser degree relative to the originalcomposition under the conditions of at least one, or both, of thestandards tests SAE J1662 (issued June 1993) and/or ASHRAE 97-1983R. Incertain more preferred embodiments, an “effective stabilizing amount” ofstabilizer comprises an amount which, when added to a compositioncomprising trifluoroiodomethane, results in a composition having astability that is at least as good as, if not better, than the stabilityof a comparable composition comprising dichlorodifluoromethane (R-12) inmineral oil, under at least one of the standard tests SAE J1662 (issuedJune 1993) and/or ASHRAE 97-1983R. Certain preferred effective amountsof stabilizer for use in the present invention comprise from about 0.001to about 10, more preferably from about 0.01 to about 5, even morepreferably from about 0.3 to about 4 weight percent, and even morepreferably from about 0.3 to about 1 weight percent based on the totalweight of trifluoroiodomethane in the composition of the presentinvention.

In certain preferred embodiments, the compositions of the presentinvention further comprise a lubricant. Any of a variety of conventionaland unconventional lubricants may be used in the compositions of thepresent invention. An important requirement for the lubricant is that,when in use in a refrigerant system, there must be sufficient lubricantreturning to the compressor of the system such that the compressor islubricated. Thus, suitability of a lubricant for any given system isdetermined partly by the refrigerant/lubricant characteristics andpartly by the characteristics of the system in which it is intended tobe used. Examples of suitable lubricants, which are generally thosecommonly used in refrigeration machinery using or designed to usehydrofluorocarbon (HFC) refrigerants, chlorofluorocarbon refrigerantsand hydrochlorofluorocarbons refrigerants, include mineral oil, siliconeoil, polyalkyl benzenes (sometimes referred to as PABs), polyol esters(sometimes referred to as POEs), polyalkylene glycols (sometimesreferred to as PAGs), polyalkylene glycol esters (sometimes referred toas PAG esters), polyvinyl ethers (sometimes referred to as PVEs),poly(alpha-olefin) (sometimes referred to as PAOs), and halocarbon oils,particularly poly(chlorotrifluorethylene) and the like. Mineral oil,which comprises paraffin oil or naphthenic oil, is commerciallyavailable. Commercially available mineral oils include Witco LP 250(registered trademark) from Witco, Zerol 300 (registered trademark) fromShrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet.Commercially available polyalkyl benzene lubricants include Zerol 150(registered trademark). Commercially available esters include neopentylglycol dipelargonate which is available as Emery 2917 (registeredtrademark) and Hatcol 2370 (registered trademark). Commerciallyavailable PAGs include Motorcraft PAG Refrigerant Compressor Oil,available from Ford, with similar products being available from Dow.Commercially available PAOs include CP-4600 from CPI Engineering.Commercially available PVEs are available from Idemitsu Kosan.Commercially available PAG esters are available from Chrysler. Otheruseful esters include phosphate esters, dibasic acid esters, andfluoroesters.

For refrigeration systems using or designed to use HFCs, it is generallypreferred to use as lubricants PAGs, PAG esters, PVEs, and POEs,particularly for systems comprising compression refrigeration,air-conditioning (especially for automotive air conditioning) and heatpumps. For refrigeration systems using or designed to use CFCs or HCFCs,it is generally preferred to use as lubricants mineral oil or PAB. Incertain preferred embodiments, the lubricants of this invention areorganic compounds which are comprised of carbon, hydrogen and oxygenwith a ratio of oxygen to carbon and are included to provide, incombination with the amounts used, effective solubility and/ormiscibility with the refrigerant to ensure sufficient return of thelubricant to the compressor. This solubility or miscibility preferablyexists at at least one temperature from about −30° C. and 70° C.

PAGs and PAG esters are highly preferred in certain embodiments becausethey are currently in use in particular applications such as originalequipment mobile air-conditioning systems. Polyol esters are highlypreferred in other certain embodiments because they are currently in usein particular non-mobile applications such as residential, commercial,and industrial air conditioning and refrigeration. Of course, differentmixtures of different types of lubricants may be used.

Uses of the Compositions

The present compositions have utility in a wide range of applications.For example, one embodiment of the present invention relates to heattransfer compositions, such as refrigerant compositions, comprising thepresent azeotrope-like compositions.

The heat transfer compositions of the present invention are generallyadaptable for use in heat transfer applications, that is, as a heatingand/or cooling medium. Although it is contemplated that the compositionsof the present invention may include the present azeotrope-likecomposition in combination with one or more other compounds orcombinations of compounds in widely ranging amounts, it is generallypreferred that heat transfer compositions of the present invention,including refrigerant compositions, consist essentially of, and in someembodiments consist of the present azeotrope-like compositions.

The heat transfer compositions of the present invention may be used inany of a wide variety of refrigeration systems includingair-conditioning (including both stationary and mobile air conditioningsystems), refrigeration, heat-pump, systems, and the like. In certainpreferred embodiments, the compositions of the present invention areused in refrigeration systems originally designed for use with an HFCrefrigerant, such as, for example, HFC-134a, combinations of methylenefluoride (HFC-32) and pentfluoroethane (HFC-125) (the combinationHFC-32:HFC-125 in approximate 50:50 weight ratio is referred to asR-410A), combinations of pentfluoroethane (HFC-125), trifluorethane(HFC-143a) and tetrafluoroethane (HFC-134a) (the combinationHFC-125:HFC-143a:HFC134a in approximate 44:52:4 weight ratio is referredto as R-404A), and the like. The preferred compositions of the presentinvention tend to exhibit many of the desirable characteristics ofR-410A and R404A and other commonly used HFC refrigerants, including aGWP that is as low as, and preferably lower than, the conventional HFCrefrigerants, and a capacity that is similar to such refrigerants. Inparticular, applicants have recognized that the present compositionstend to exhibit relatively low global warming potentials (“GWPs”),preferably less than about 1000, more preferably less than about 500,and even more preferably less than about 150. In addition, therelatively constant boiling nature of the compositions of the presentinvention makes them even more desirable than certain conventional HFCs,such as R-404A or combinations of HFC-32, HFC-125 and HFC-134a (thecombination HFC-32:HFC-125:HFCI34a in approximate 23:25:52 weight ratiois referred to as R-407C), for use as refrigerants in many applications.

In certain other preferred embodiments, the present compositions areused in heat transfer systems in general, and in refrigeration systemsin particular, originally designed for use with a CFC or HCFCrefrigerant. Preferred refrigeration compositions of the presentinvention may be used in refrigeration systems containing a lubricantused conventionally with CFC-refrigerants, such as mineral oils,polyalkylbenzene oils, polyalkylene glycols, and the like, or may beused with other lubricants traditionally used with HFC refrigerants. Asused herein the term “refrigeration system” refers generally to anysystem or apparatus, or any part or portion of such a system orapparatus, which employs a refrigerant to provide cooling. Suchrefrigeration systems include, for example, air conditioners, electricrefrigerators, chillers (including chillers using centrifugalcompressors), transport refrigeration systems, commercial refrigerationsystems and the like.

Many existing refrigeration systems are currently adapted for use inconnection with existing refrigerants, and the compositions of thepresent invention are believed to be adaptable for use in many of suchsystems, either with or without system modification. In manyapplications the compositions of the present invention may provide anadvantage as a replacement in smaller systems currently based on certainrefrigerants, for example those requiring a small refrigerating capacityand thereby dictating a need for relatively small compressordisplacements. Furthermore, in embodiments where it is desired to use alower capacity refrigerant composition of the present invention, forreasons of efficiency for example, to replace a refrigerant of highercapacity, such embodiments of the present compositions provide apotential advantage. Thus, it is preferred in certain embodiments to usecompositions of the present invention, particularly compositionscomprising a substantial proportion of, and in some embodimentsconsisting essentially of the present azeotrope-like compositions, as areplacement for existing refrigerants, such as HFC-134a; CFC-12;HCFC-22; methylene fluoride (HFC-32); HFC-152a; combinations ofpentfluoroethane (HFC-125), trifluorethane (HFC-143a) andtetrafluoroethane (HFC-134a) (the combination HFC-125:HFC-143a:HFC134ain approximate 44:52:4 weight ratio is referred to as R-404A);combinations of HFC-32, HFC-125 and HFC-134a (the combinationHFC-32:HFC-125:HFC134a in approximate 23:25:52 weight ratio is referredto as R-407C); combinations of methylene fluoride (HFC-32) andpentfluoroethane (HFC-125) (the combination HFC-32:HFC-125 inapproximate 50:50 weight ratio is referred to as R-410A); thecombination of CFC-12 and 1,1-difluorethane (HFC-152a) (the combinationCFC-12:HFC-152a in a 73.8:26.2 weight ratio is referred to R-500); andcombinations of HFC-125 and HFC-143a (the combination HFC-125:HFC143a inapproximate 50:50 weight ratio is referred to as R-507A). In certainembodiments it may also be beneficial to use the present compositions inconnection with the replacement of refrigerants formed from thecombination HFC-32:HFC-125:HFC 134a in approximate 20:40:40 weightratio, which is referred to as R-407A, or in approximate 15:15:70 weightratio, which is referred to as R-407D. Heat transfer compositions of thepresent invention are particularly preferred as replacements for R-22,R-32, R-404A, R-407A, R-407C, R-407D, R-410A and R-507A. The presentcompositions are also believed to be suitable as replacements for theabove noted compositions in other applications, such as aerosols,blowing agents and the like.

In certain applications, the refrigerants of the present inventionpotentially permit the beneficial use of larger displacementcompressors, thereby resulting in better energy efficiency than otherrefrigerants, such as HFC-134a. Therefore the refrigerant compositionsof the present invention provide the possibility of achieving acompetitive advantage on an energy basis for refrigerant replacementapplications.

It is contemplated that the compositions of the present also haveadvantage (either in original systems or when used as a replacement forrefrigerants such as CFC-12, HCFC-22, HFC-134a, HFC-152a, R-404A,R-410A, R-407C, R-507A and R-500), in chillers typically used inconnection with commercial and industrial air conditioning andrefrigeration systems. In certain of such embodiments it is preferred toincluding in the present compositions from about 0.5 to about 15% of asupplemental flammability suppressant and in certain cases morepreferably from about 0.5 to about 10% on a weight basis. In this regardit is noted that the CF₃I component of the present compositions may incertain embodiments act as flammability suppressants with respect toother components in the composition. Thus, components other than CF₃Iwhich have flammability suppressant functionality in the compositionwill sometimes be referred to herein as a supplemental flammabilitysuppressant. Likewise, applicants have come to appreciate that the CF₃Icomponent of the present compositions may in certain embodiments act aslubricant, and therefore components other than CF₃I which havelubrication functionality will sometime be referred to herein as asupplemental lubricants.

In certain embodiments, co-refrigerants, including for example HFCs,HCFCs and CFCs may be included in the heat transfer compositions of thepresent invention, including one or more of the following compounds,including any and all isomers thereof:

Trichlorofluoromethane (CFC-11)

Dichlorodifluoromethane (CFC-12)

Pentafluoroethane (HFC-125)

1,1,2,2-tetrafluoroethane (HFC-134)

1,1,1,2-Tetrafluoroethane (HFC-134a)

Difluoroethane (HFC-152a)

1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea)

1,1,1,3,3,3-hexafluoropropane (HFC-236fa)

1,1,1,3,3-pentafluoropropane (HFC-245fa)

1,1,1,3,3-pentafluorobutane (HFC-365mfc)

water

CO₂

The relative amount of any of the above noted components, as well as anyadditional components which may be included in present compositions, maybe incorporated into the present composition in amounts depending on theparticular application for the composition, and all such relativeamounts are considered to be within the scope hereof, providedpreferably that such components do not negate the azeotrope-like natureof the compositions described herein.

The present methods, systems and compositions are thus adaptable for usein connection with automotive air conditioning systems and devices,commercial refrigeration systems and devices, chillers (includingsystems which utilize centrifugal compressors), residential refrigeratorand freezers, general air conditioning systems, heat pumps, and thelike.

Any of a wide range of methods for introducing the present refrigerantcompositions to a refrigeration system can be used in the presentinvention. For example, one method comprises attaching a refrigerantcontainer to the low-pressure side of a refrigeration system and turningon the refrigeration system compressor to pull the refrigerant into thesystem. In such embodiments, the refrigerant container may be placed ona scale such that the amount of refrigerant composition entering thesystem can be monitored. When a desired amount of refrigerantcomposition has been introduced into the system, charging is stopped.Alternatively, a wide range of charging tools, known to those of skillin the art, is commercially available. Accordingly, in light of theabove disclosure, those of skill in the art will be readily able tointroduce the refrigerant compositions of the present invention intorefrigeration systems according to the present invention without undueexperimentation.

According to certain other embodiments, the present invention providesrefrigeration systems comprising a refrigerant of the present inventionand methods of producing heating or cooling by sensible heat transferand/or condensing and/or evaporating a composition of the presentinvention. In certain preferred embodiments, the methods for cooling,including cooling of other fluid either directly or indirectly or a bodydirectly or indirectly, an article according to the present inventioncomprise condensing a refrigerant composition comprising anazeotrope-like composition of the present invention and thereafterevaporating said refrigerant composition in the vicinity of the fluid orbody to be cooled. As used herein, the term “body” is intended to refernot only to inanimate objects but also to living tissue, includinganimal tissue in general and human tissue in particular. For example,certain aspects of the present invention involved application of thepresent composition to human tissue for one or more therapeuticpurposes, such as a pain killing technique, as a preparatory anesthetic,or as part of a therapy involving reducing the temperature of the bodybeing treated. In certain embodiments, the application to the bodycomprises providing the present compositions in liquid form underpressure, preferably in a pressurized container having a one-waydischarge valve and/or nozzle, and releasing the liquid from thepressurized container by spraying or otherwise applying the compositionto the body. As the liquid evaporates from the surface being sprayed,the surface cools.

Certain preferred methods for heating a fluid or body comprisecondensing a refrigerant composition comprising an azeotrope-likecomposition of the present invention in the vicinity of the article tobe heated and thereafter evaporating said refrigerant composition. Inlight of the disclosure herein, those of skill in the art will bereadily able to heat and cool articles according to the presentinventions without undue experimentation.

In another embodiment, the azeotrope-like compositions of this inventionmay be used as propellants in sprayable compositions, either alone or incombination with known propellants. The propellant compositioncomprises, more preferably consists essentially of, and, even morepreferably, consists of the azeotrope-like compositions of theinvention. The active ingredient to be sprayed together with inertingredients, solvents, and other materials may also be present in thesprayable mixture. Preferably, the sprayable composition is an aerosol.Suitable active materials to be sprayed include, without limitation,cosmetic materials such as deodorants, perfumes, hair sprays, cleaningsolvents, and lubricants, as well as medicinal materials such asanti-asthma and anti-halitosis medications. The term medicinal materialsis used herein in its broadest sense to include any and all materialswhich are, or at least are believe to be, effective in connection withtherapeutic, diagnostic, pain relief, and similar treatments, and assuch would include for example drugs and biologically active substances.

Yet another embodiment of the present invention relates to a blowingagent comprising one or more azeotrope-like compositions of theinvention. In general, the blowing agent may include the azeotrope-likecompositions of the present invention in widely ranging amounts. It isgenerally preferred, however, that the blowing agents comprise thepresent azeotrope-like compositions in amounts at least about 5% byweight, and even more preferably at least about 15% by weight, of theblowing agent. In certain preferred embodiments, the blowing agentcomprises at least about 50% by weight of the present azeotrope-likecompositions, and in certain embodiments the blowing agent consistsessentially of or consist of the present azeotrope-like composition. Incertain preferred embodiments, the blowing agent includes, in additionto the present compositions, one or more of co-blowing agents, fillers,vapor pressure modifiers, flame suppressants, stabilizers and likeadjuvants.

In other embodiments, the invention provides foamable compositions. Thefoamable compositions of the present invention generally include one ormore components capable of forming foam having a generally cellularstructure and a blowing agent in accordance with the present invention.In certain embodiments, the one or more components comprise athermosetting composition capable of forming foam and/or foamablecompositions. Examples of thermosetting compositions includepolyurethane and polyisocyanurate foam compositions, and also phenolicfoam compositions. In such thermosetting foam embodiments, one or moreof the present compositions are included as or part of a blowing agentin a foamable composition, or as a part of a two or more part foamablecomposition, which preferably includes one or more of the componentscapable of reacting and/or foaming under the proper conditions to form afoam or cellular structure. In certain other embodiments, the one ormore components comprise thermoplastic materials, particularlythermoplastic polymers and/or resins. Examples of thermoplastic foamcomponents include polyolefins, such as polystyrene (PS), polyethylene(PE), polypropylene (PP) and polyethyleneterepthalate (PET), and foamsformed therefrom, preferably low-density foams. In certain embodiments,the thermoplastic foamable composition is an extrudable composition.

It will be appreciated by those skilled in the art, especially in viewof the disclosure contained herein, that the order and manner in whichthe blowing agent of the present invention is formed and/or added to thefoamable composition does not generally affect the operability of thepresent invention. For example, in the case of extrudable foams, it ispossible that the various components of the blowing agent, and even thecomponents of the present composition, be not be mixed in advance ofintroduction to the extrusion equipment, or even that the components arenot added to the same location in the extrusion equipment. Thus, incertain embodiments it may be desired to introduce one or morecomponents of the blowing agent at first location in the extruder, whichis upstream of the place of addition of one or more other components ofthe blowing agent, with the expectation that the components will cometogether in the extruder and/or operate more effectively in this manner.Nevertheless, in certain embodiments, two or more components of theblowing agent are combined in advance and introduced together into thefoamable composition, either directly or as part of premix which is thenfurther added to other parts of the foamable composition.

The invention also relates to foam, and preferably closed cell foam,prepared from a polymer foam formulation containing a composition of theinvention, preferably as part of blowing agent.

In certain preferred embodiments, dispersing agents, cell stabilizers,surfactants and other additives may also be incorporated into theblowing agent compositions of the present invention. Surfactants areoptionally but preferably added to serve as cell stabilizers. Somerepresentative materials are sold under the names of DC-193, B-8404, andL-5340 which are, generally, polysiloxane polyoxyalkylene blockco-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748,2,917,480, and 2,846,458, each of which is incorporated herein byreference. Other optional additives for the blowing agent mixture mayinclude flame retardants or suppressants such astri(2-chloroethyl)phosphate, tri(2-chloropropyl)phosphate,tri(2,3-dibromopropyl)-phosphate, tri(1,3-dichloropropyl) phosphate,diammonium phosphate, various halogenated aromatic compounds, antimonyoxide, aluminum trihydrate, polyvinyl chloride, and the like.

Any of the methods well known in the art, such as those described in“Polyurethanes Chemistry and Technology,” Volumes I and II, Saunders andFrisch, 1962, John Wiley and Sons, New York, N.Y., which is incorporatedherein by reference, may be used or adapted for use in accordance withthe foam embodiments of the present invention.

Other uses of the present azeotrope-like compositions include use assolvents, cleaning agents, and the like. Those of skill in the art willbe readily able to adapt the present compositions for use in suchapplications without undue experimentation.

EXAMPLE

The invention is further illustrated in the following example which isintended to be illustrative, but not limiting in any manner.

Example 1

An ebulliometer consisting of vacuum jacketed tube with a condenser ontop which is further equipped with a Quartz Thermometer K96S4771 isused. About 20 g HFC-32 is charged to the ebulliometer and then CF₃I isadded in small, measured increments. Temperature depression is observedwhen CF₃I is added to HFC-32, indicating a binary minimum boilingazeotrope is formed. From greater than about 0 to about 33 weightpercent CF₃I, the boiling point of the composition changed by about 2°C. or less. The binary mixtures shown in Table 1 were studied and theboiling point of the compositions changed by about 2° C. or less. Thecompositions exhibit azeotrope and/or azeotrope-like properties overthis range.

TABLE 1 HFC-32/CF₃I compositions at 14.51 psia Wt. % HFC-32 Wt. % CF₃ITemperature (° C.) 100.00 0.00 −53.000 98.26 1.74 −53.301 93.70 6.30−53.742 90.24 9.76 −53.742 84.86 15.14 −53.451 72.88 27.12 −52.098 67.2632.74 −51.948

1. A refrigeration system comprising a heat transfer composition, saidcomposition comprises at least about 50% by weight of an azeotrope-likecomposition comprising effective amounts of HFC-32 and CF₃I.
 2. Arefrigeration system of claim 1 selected from group consisting ofautomotive air conditioning systems, residential air conditioningsystems, commercial air conditioning systems, residential refrigeratorsystems, residential freezer systems, commercial refrigerator systems,commercial freezer systems, chiller air conditioning systems, chillerrefrigeration systems, heat pump systems, and combinations of two ormore of these.